Doggles ILS are the first and only protective eyewear designed just for dogs! 15 years of experience has made our Doggles ILS (Interchangeable Lens System) the very best in pet eyewear for fashion or protection. All Doggles lens are anti-fog, shatterproof, and offers 100% UV protection. Extra wide nose bridge, deep lens cup, padded and flexible rubber frame, soft elastic adjustable head and chin straps, are just some of the features that make this the best possible solution for your pet's eyewear needs. Important: When sizing your dog for Doggles, it is necessary to measure your dog's head, because body proportions vary greatly. Sizing Information: To determine proper back strap and frame length, measure the entire head circumference across the eyes and around under the ears. To determine proper chin strap length, start measurement just under one ear, go under the chin and back up to under the other ear.